Organic material (e.g., blood clots, tissue, and biological concretions such as urinary, biliary, and pancreatic stones) or inorganic material (e.g., components of medical devices or other foreign matter) may sometimes obstruct or otherwise be present within the body's anatomical lumens, such as the biliary tree. For example, biological concretions can develop in certain parts of the body, such as kidneys, pancreas, and gallbladder. Minimally invasive medical procedures generally involve causing limited trauma to the tissues of the patient, and can be used to dispose of certain problematic biological concretions or similarly unwanted obstructions.
Many medical retrieval devices can be used to entrap an object, such as tissue or a stone fragment, and drag it through an ampulla (i.e., a small dilatation in the patient's anatomical lumen) to remove it. Such medical retrieval devices include, for example, retrieval baskets and may be used through an endoscope or laparoscope. However, occasionally an object may be too large to be extracted through an ampulla.
With many known retrieval assemblies, it is difficult to cut the entrapped material, such as tissue or a stone, once the material is entrapped to reduce the size of the material. For example, in some patients, a cicatrix or some other constriction that reduces the diameter of a body lumen may form within the lumen. The narrowed lumen may not interfere or prevent normal insertion of a retrieval device. However, after the retrieval device is inserted into the tract, the retrieval assembly expands, and an object is captured within the device. At this point, the diameter of the retrieval assembly containing the entrapped object may exceed the inner diameter of the narrowed lumen. Under these circumstances, it may be desirable to reduce the size of the entrapped object so that the retrieval assembly and the entrapped object may be safely removed from the lumen. Other circumstances may be encountered during a medical retrieval procedure that may also require cutting an entrapped object within a retrieval device.
The present disclosure provides medical retrieval devices and methods of using the same that address some or all of the aforementioned shortcomings of the existing devices.